Air conditioner for vehicles

Abstract

Provided is a refrigerant cycle of an air conditioner for vehicles, and more particularly, a refrigerant cycle of an air conditioner for vehicles having a first evaporating unit and a second evaporating unit disposed upstream and downstream in a direction in which air blown from a single blower flows to control an amount of the refrigerant supplied to each evaporating unit, thereby making it possible to obtain optimal radiating performance (cooling performance) and cooling efficiency (COP) through the design of the optimal refrigerant flow ratio depending on the cooling load.

The invention claimed is: 
     
       1. An air conditioner for vehicles, comprising:
 a compressor for sucking and compressing a refrigerant; 
 a condenser for condensing the refrigerant compressed in the compressor; 
 an expansion unit for expanding the refrigerant after branching the refrigerant discharged from the condenser; and 
 an evaporator including a first evaporating unit and a second evaporating unit each for receiving and evaporating the expanded refrigerants branched from the expansion unit, wherein the expansion unit comprises:
 a first expansion valve; and 
 a second expansion valve, wherein a discharge from the condenser is branched to a pair of branch passages, with an expansion valve of the first and second expansion valves being provided on each branch passage of the pair of branch passages, and the first expansion valve and the second expansion valve are arranged in a parallel configuration and configured to allow the refrigerant to be distributed into the first evaporating unit and the second evaporating unit, respectively, to control the refrigerant flow ratio, and wherein the first evaporating unit and the second evaporating unit are arranged in a parallel configuration, 
 wherein the first evaporating unit is disposed upstream and the second evaporating unit is disposed downstream, in a direction in which air blown from a single blower flows, and the first evaporating unit and the second evaporating unit are disposed to be contacted to each other, 
 wherein the first evaporating unit and the second evaporating unit are configured to simultaneously receive the refrigerant which has passed through the expansion unit, and 
 wherein the first evaporating unit disposed upstream in the air flowing direction is supplied with a relatively larger amount of refrigerant than the second evaporating unit disposed downstream. 
 
 
     
     
       2. The refrigerant cycle of an air conditioner for vehicles of  claim 1 , wherein a refrigerant flow ratio distributed into the first evaporating unit and the second evaporating unit, respectively, is in a range of 58%:42%˜75%:25%. 
     
     
       3. The refrigerant cycle of an air conditioner for vehicles of  claim 1 , wherein the first evaporating unit and the second evaporating unit are formed so that the single evaporator is separated into two evaporation regions.